1. Field of the Invention
The present invention relates to surgical instruments. More particularly, this invention relates to a surgical instrument, such as a biopsy forceps device, that includes a locking feature for maintaining end effectors in an open relation during removal of a tissue sample, and relates to a related method of removing a tissue sample.
2. Background of the Related Art
An endomyocardial biopsy forceps device is used to obtain biopsy tissue samples from the interior walls of heart chambers. Such samples are often used to characterize rejection factors in the hearts of transplant recipients or for other diagnostic applications.
A typical biopsy forceps includes a long flexible catheter portion having a pair of opposed jaws at a distal end and a manual actuator at the proximal end. Manipulation of the actuator opens and closes the jaws.
During a biopsy tissue sample procedure, the physician first inserts the catheter portion into an appropriately sized introducer sheath. Under ultrasound or other visual technique, the physician then guides the catheter portion through a long tortuous passageway, such as a vein or an artery, until the jaws are positioned by a tissue sample site of an interior wall of the chamber. The physician then opens the jaws, positions the jaws around the tissue to be sampled, and manipulates the actuator so that the jaws close around the tissue. A sample of the tissue is then cut from the biopsy site while it is trapped between the jaws. Keeping the jaws closed, the physician withdraws the biopsy forceps and opens the jaws to collect the biopsy tissue sample.
During removal of a tissue sample from the device, the physician must maintain the jaws in an open relationship. With conventional endomyocardial biopsy forceps, the physician must manipulate the actuator handle to maintain the open relationship and, at the same time, remove the sample. Performing both of these steps at the same time typically requires the aid of another person. The need exists therefore for a biopsy forceps and a related method in which tissue samples can be removed more easily.
Conventional endomyocardial biopsy forceps typically also include an end effector assembly made of multiple parts requiring rivets or other fasteners to hold the assembly together. Such a construction increases the manufacturing cost and assembly time. An end effector assembly with less parts and a simpler construction therefore is desired.
The end effector assembly retains the opposed jaws. Each jaw typically includes a cup at its distal end to retain the biopsy sample. The edges of the cup perform the cutting operation. Because the jaw is small and difficult to machine and the edges must be very sharp, conventional machining techniques often result in rough, pitted jaws with burrs. Therefore, a process for achieving a burr free, polished jaw with sharp edges and an acceptable cosmetic appearance is desired.